We will continue work on the roles of the adenine nucleotides on metabolic regulation and correlation. In each case, effects of other metabolites on the adenylate energy charge responses of the systems studied will be looked for. We intend to look at glucose-6-P dehydrogenase, transaldolase, and transketolase in the pentose phosphate pathway, and to look again for possible regulatory interactions between phosphofructokinase and fructose diphosphatase. Effects of adenine nucleotides and other modifiers on the coupled conversion carried out by glutamine synthase and glutamate synthase will be studied. The effects of imbalances in the ratios among the adenine nucleotides will be studied with the use of a temperature-sensitive adenylate kinase mutant strain of Escherichia coli. BIBLIOGRAPHIC REFERENCES: W.J. Ball and D.E. Atkinson, 1975. Adenylate energy charge in Saccharomyces cerevisiae during starvation. J. Bacteriol. 121, 975. A.G. Chapman, A.L. Miller, and D.E. Atkinson, 1976. Role of the adenylate deaminase reaction in regulation of adenine metabolism in Ehrlich ascites tumor cells. Cancer Research 36, 1144.